WFAA-TV

HIGHLAND PARK, TEXAS - While most people tend to blame the store when their milk goes bad, beer gets skunky or the lettuce welts, they may be pointing their finger in the wrong direction.

From bagged salads to milk to canned vegetables and beer, Americans are obsessed with freshness. Experts say as many as 65 percent of those scouring the grocery store look for the best expiration dates.

But before milk hits the bottle, it has already begun its funeral march towards fermentation.

"The lactic acid bacteria are starting to multiply," said Paul Neill, Quality Director for Dean's Foods.

Stores, like Central Market, go to great lengths to bring fresh produce by keeping the air in the produce section chilled to 65 degrees, and even placing some vegetables on ice. Then here comes the consumer, who goes and places those delicate green onions in the furnace they call the family car.

"It's not just up to the stores and retail establishments, it's also up to the consumer," said Carolyn Bednar, a food scientist at Texas Woman's University.

Joe Sandro, the produce buyer for Central Market, said there are easy steps consumers can take to keep perishable items fresh.

"Turn on the air conditioning as quickly as possible," he said. "Produce is a perishable item. When it hits that hot air it starts degrading."

Many people don't realize their actions are quickening the demise of their recently purchased foods and beverages.

For example, the milk expiration gives people 14 days to drink. But those at Schepp's Dairy said whether it actually makes it that long depends on the purchaser. For every one degree milk is stored above 40 degrees, it loses two days of its shelf life.

"If the temperature were to rise that milk up to 50 degrees you probably got two days left on your milk for shelf life," Neill said. "It will spoil very fast."

Those at the Rahr Brewery in Fort Worth said they take great care in crafting great tasting beer.

Brewing Manager, Mark Wedge, said beer loses flavor over time, and eventually starts to taste like cardboard. So, he said those freshness dates are important.

"You're able to know that beer hasn't been sitting on a shelf for a year or so," he said.

While some beer dates are up front, others require a secret decoder ring.

Either way, Wedge said keeping beer cold keeps it fresher longer.

"Your refrigerator should be set at 33 to 34, absolutely, in the summer time here in Texas," he said.

So, if one should remember nothing else from this story, remember this, go buy a fridge thermometer. The average North Texas family spends almost $4,000 a year on food, which seems an amount worth protecting.